PHILADELPHIA (CBS) — The Philadelphia Gas Works is facing a lengthy complaint, and a potentially hefty fine, from the Pennsylvania Public Utility Commission in the wake of an explosion last January in the Tacony section of the city that killed one PGW worker, injured five others, and rattled a neighborhood to its core.

The 24-page report(.pdf format) concludes that PGW failed to follow many of its own safety procedures on site, including taking too long to shut off gas and electricity in the area where gas was leaking (see previous story).

Also, those who responded were not tested for drug or alcohol use afterward.

PGW spokesman Barry O’Sullivan says the utility has its own conclusions. So does the Philadelphia Fire Department, and all will be compared to the PUC’s findings.

“If there are any areas where our findings have shown up distinct differences, I think that’s where we need to work very closely with them,” O’Sullivan told KYW Newsradio.

The PUC’s fine structure calls for more than $3 million in penalties for the more than 300 alleged violations, but the cap for a single incident is $500,000.

PGW has 20 days to respond, but this process could drag on for months. In a written statement released today, PGW said in part, “Currently we are reviewing the content of the report and will respond to its various claims during the formal review process that will now begin.”